Toner cartridge and image forming apparatus

Abstract

An image forming apparatus includes a toner cartridge that supplies toner to an image carrier. The toner cartridge includes a development unit that is connected to a toner container via a connection hole, and has an external opening for supplying the toner to the image carrier, an outer shutter that opens and closes the external opening, an inner shutter that opens and closes the connection hole, and a gear mechanism that connects the outer shutter and the inner shutter to be capable of interlocking with each other. When outer shutter is in a first closing position to close the external opening, the inner shutter is in a second closing position to close the connection hole. When the outer shutter is in a first opening position to open the external opening, the inner shutter is in a second opening position to open the connection hole.

What is claimed is: 
     
       1. A toner cartridge configured to supply toner to an electrostatic latent image formed on an image carrier, so as to develop the same into a toner image, the toner cartridge comprising:
 a toner container configured to store the toner; 
 a development unit connected to the toner container via a connection hole, the development unit having an external opening on its outer periphery surface so as to supply the toner to the image carrier; 
 a toner carrier disposed in the development unit in a rotatable manner, so as to face the image carrier, the toner carrier carrying the toner; 
 an outer shutter configured to open and close the external opening; 
 an inner shutter configured to open and close the connection hole; and 
 a gear mechanism configured to connect the outer shutter and the inner shutter to be capable of interlocking with each other, wherein 
 the outer shutter is movable at least between a first closing position to close the external opening and a first opening position to open the external opening, 
 the inner shutter is movable at least between a second closing position to close the connection hole and a second opening position to open the connection hole, and 
 when the outer shutter is in the first closing position, the inner shutter is in the second closing position, while when the outer shutter is in the first opening position, the inner shutter is in the second opening position. 
 
     
     
       2. The toner cartridge according to  claim 1 , further comprising a biasing member configured to bias the outer shutter toward the first closing position. 
     
     
       3. An image forming apparatus comprising:
 an image carrier having a surface on which an electrostatic latent image is formed; and 
 the toner cartridge according to  claim 2 , configured to supply toner to the electrostatic latent image formed on the image carrier, so as to develop a toner image. 
 
     
     
       4. The image forming apparatus according to  claim 3 , comprising an image carrier holding section configured to hold the image carrier in a rotatable manner, wherein
 the outer shutter has an opening and closing boss configured to contact the image carrier holding section so as to move the outer shutter to the first opening position. 
 
     
     
       5. The toner cartridge according to  claim 1 , wherein the outer shutter and the gear mechanism are connected to each other via a link mechanism. 
     
     
       6. An image forming apparatus comprising:
 an image carrier having a surface on which an electrostatic latent image is formed; and 
 the toner cartridge according to  claim 5 , configured to supply toner to an electrostatic latent image formed on the image carrier, so as to develop a toner image. 
 
     
     
       7. The image forming apparatus according to  claim 6 , comprising an image carrier holding section configured to hold the image carrier in a rotatable manner, wherein
 the outer shutter has an opening and closing boss configured to contact the image carrier holding section so as to move the outer shutter to the first opening position. 
 
     
     
       8. An image forming apparatus comprising:
 an image carrier having a surface on which an electrostatic latent image is formed; and 
 the toner cartridge according to  claim 1 , configured to supply toner to the electrostatic latent image formed on the image carrier, so as to develop a toner image. 
 
     
     
       9. The image forming apparatus according to  claim 8 , comprising an image carrier holding section configured to hold the image carrier in a rotatable manner, wherein
 the outer shutter has an opening and closing boss configured to contact the image carrier holding section so as to move the outer shutter to the first opening position.